1. Field of the Invention
The invention generally relates to vehicles, more specifically the present invention relates to powered vehicles that can drive on land, fly in the air and move on the surface of water; most specifically the present invention is an autogiro that can operate as a motorcycle on land and can also operate as an aircraft.
2. Description of the Related Art
Since the invention of the airplane, people have sought to make practical vehicles that can travel both through the air and on the earth's surface. Among the earliest attempts at such vehicles were roadable gyroplanes. Roadable gyroplanes have long been driven on three or more wheels on land. The present inventor is unaware of any roadable gyroplane meant to be driven on two wheels. The “Pitcairn AC35”, built in the 1930's, is an early design of a three wheel roadable tractor style gyroplane in which the propeller is at the front of the aircraft with the cabin behind the propeller and an engine behind the cabin. A long drive shaft connects the engine to the propeller. The AC35 has conventional landing gear and rear wheel drive. The AC35 is steered by the rear wheel, which results in poor handling characteristics and makes the vehicle difficult to drive. The AC35 has a nose-high conventional landing gear configuration because the propeller blades require a high nose angle when the tail wheel is on the ground to provide propeller clearance after rotation. That high nose angle makes it very difficult to see out of the front during ground operations. Traditionally, pilots taxiing such craft make wide swings to the right and left to look out the side windows. More recent three-wheel roadable gyroplanes employ a pusher configuration, where the propeller is behind the engine and the cabin is in front. Examples include the Super Sky Cycle and the Super Sky Car from New Horizon Components and a Magni gyroplane converted by Sean Cooper to be legally drivable on the road. U.S. Pat. No. 6,978,969 to Larry R. Neal discloses a fly-drive vehicle including a transmission for selectively transferring mechanical power from the motor to one of the of wheels or to the drive propeller, and a landing gear assembly for raising and lowering the pair of wheels, and a folding rotor shaft assembly for raising and lowering the rotor.
Floating gyroplanes that use the thrust of the flight propeller to taxi on water are also possible, such as those built by James Leszie.
Volante Aircraft is currently developing a roadable airplane, consisting of a flight section that is removable from the car component, and that is transportable by the car in trailer fashion. At flight time, the flight section is re-attached to the automobile.
U.S. Pat. No. 6,106,054 discloses a motorcycle enclosed in a monocoque fairing, an embodiment of which is known as the Peraves Ecomobile that uses retractable stabilizer wheels to keep the vehicle upright at low speeds. Though Ragallo wings (U.S. Pat. No. 4,068,810) have been attached to motorcycles and powered parachutes have been attached to motorcycles (U.S. Pat. No. 6,877,690), the present inventor is not aware of any motorcycle in the prior art (whether enclosed in a monocoque fairing or not) that is capable of flight as an autogiro.
U.S. Pat. No. 3,870,251 discloses an autogiro designed by Gerald Breuner (the Breuner Autogiro) with the cabin in front of the propeller and the engine in the rear. The cabin and the engine are connected by struts to an annular duct in which the propeller is located. The present inventor is not aware of any autogiro in this configuration that does not have such an annular duct or equivalent structure (such as struts forming a space frame) connecting the engine to the cabin. Mounted between the cabin and propeller of the Breuner Autogiro is a gearbox and clutch arrangement. A shaft extends forwardly from the engine to said gearbox and clutch arrangement, and a hollow coaxial shaft extends back from said gearbox to said propeller. The present inventor is not aware of any autogiro in the Breuner Autogiro configuration that is roadable or in which structural members connecting the cabin to the engine pass primarily through a propeller barrel.
The Breuner Autogiro offers many advantages over other autogiro configurations. The forward mounted cabin provides good visibility to the pilot. Having the engine in the slipstream of the propeller helps with cooling and eliminates the possibility of engine parts coming loose and causing damage to the propeller. It is safer to have the engine farther from the cabin in case of fire and this arrangement also helps with engine noise because the slipstream carries engine noise away from the cabin. Also, in this configuration the propeller is close to the pylon and the landing gear, where the height profile under the rotor is greatest, allowing for a larger propeller and lower mounted engine. This configuration is also favorable for balancing the weight of the engine and cabin. Having a forward facing engine behind the pylon also allows for direct power take-off from the propeller shaft to prerotate the rotor for take-off. A disadvantage of the Breuner Autogiro is that the annular duct and associated structure adds significant frontal area and overall size to the vehicle, making it unsuitable as a roadable vehicle.